Work from this laboratory has shown that conjugates of ragweed antigen E with methoxy-polyethylene glycol (PEG) have reduced allergenic activities when compared to the native antigen. Studies in mice showed that these conjugates are apparently non-immunogenic in mice, and that they retain the immunosuppresive property of the native antigen for IgE and IgG antibody responses. These studies will be continued and expanded with conjugates of ragweed antigen E with different alkoxy-PEGs. Different chemical modifications of antigen E and its degradation into fragments will be made for the purpose of identifying its antigenic determinants recognized by B and T cell receptors.